ICES Advice 2013, Book 9 1 9.4.17 Advice October 2013 ECOREGION Widely distributed and migratory stocks STOCK Mackerel in the Northeast Atlantic (combined Southern, Western, and North Sea spawning components) Advice for 2014 ICES advises on the basis of the recent three years’ landings (see Quality considerations) that landings should be no more than 889 886 t in 2014. Discards are known to take place, but cannot be quantified accurately; therefore total catches cannot be calculated. ICES advises that the existing measures to protect the North Sea spawning component should remain in place. Stock status 0 1000 2000 3000 4000 5000 6000 1990 1995 2000 2005 2010 2015 SSB index Figure 9.4.17.1 Mackerel in the Northeast Atlantic. Landings in thousand tonnes (left) and SSB index from the triennial mackerel egg survey (right). Confidence intervals are currently not available for the egg survey index. In the catch plot the years prior to 2005 are shaded, indicating that the catch data are less certain in these years. Catches of mackerel have been increasing since 2005 and have been around 900 kt since 2010. The mackerel egg survey index show a doubling of the SSB since 2004, and a 30% increase from 2010 to 2013 (a preliminary value). Management plan A management plan was agreed by Norway, Faroe Islands, and the EU in October 2008. ICES has evaluated the plan and concluded that it is precautionary (ICES, 2008). However, since 2009, there has been no international agreement on TAC. The plan requires an agreed assessment which is currently not available for this stock. Biology The combined Northeast Atlantic (NEA) mackerel is assessed as one stock, but comprises three spawning components. Spawning areas of mackerel are widely spread, and only the North Sea component is sufficiently distinct to be clearly identified as a separate spawning component. Mackerel from the southern and western areas migrate to feed in the Nordic seas and the North Sea during the second half of the year, and then mix with the North Sea component. F (Fishing Mortality) 2010–2012 Qualitative evaluation Insufficient information SSB (Spawning-Stock Biomass) 2004–2013 Qualitative evaluation Steady increase
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ICES Advice 2013, Book 9 1
9.4.17 Advice October 2013 ECOREGION Widely distributed and migratory stocks STOCK Mackerel in the Northeast Atlantic (combined Southern, Western, and
North Sea spawning components) Advice for 2014 ICES advises on the basis of the recent three years’ landings (see Quality considerations) that landings should be no more than 889 886 t in 2014. Discards are known to take place, but cannot be quantified accurately; therefore total catches cannot be calculated. ICES advises that the existing measures to protect the North Sea spawning component should remain in place. Stock status
0
1000
2000
3000
4000
5000
6000
1990 1995 2000 2005 2010 2015
SSB
inde
x
Figure 9.4.17.1 Mackerel in the Northeast Atlantic. Landings in thousand tonnes (left) and SSB index from the triennial
mackerel egg survey (right). Confidence intervals are currently not available for the egg survey index. In the catch plot the years prior to 2005 are shaded, indicating that the catch data are less certain in these years.
Catches of mackerel have been increasing since 2005 and have been around 900 kt since 2010. The mackerel egg survey index show a doubling of the SSB since 2004, and a 30% increase from 2010 to 2013 (a preliminary value). Management plan A management plan was agreed by Norway, Faroe Islands, and the EU in October 2008. ICES has evaluated the plan and concluded that it is precautionary (ICES, 2008). However, since 2009, there has been no international agreement on TAC. The plan requires an agreed assessment which is currently not available for this stock. Biology The combined Northeast Atlantic (NEA) mackerel is assessed as one stock, but comprises three spawning components. Spawning areas of mackerel are widely spread, and only the North Sea component is sufficiently distinct to be clearly identified as a separate spawning component. Mackerel from the southern and western areas migrate to feed in the Nordic seas and the North Sea during the second half of the year, and then mix with the North Sea component.
F (Fishing Mortality) 2010–2012
Qualitative evaluation Insufficient information SSB (Spawning-Stock Biomass) 2004–2013
Environmental influence on the stock Catch and survey data from recent years indicate that the stock has expanded north-westwards during spawning and the summer feeding migration. This distributional change is likely a reflection of increased stock size coupled with changes in the physical environment and in the zooplankton concentration and distribution. The fisheries Traditionally, the fishing areas with higher catches of mackerel have been in the northern North Sea (along the border of Divisions IVa and IIa), around the Shetland Islands, and off the west coast of Scotland and Ireland. The southern fishery off Spain’s northern coast has also accounted for significant catches. In recent years significant catches have also been taken in Icelandic and Faroese waters, areas where almost no catches were reported prior to 2008. In 2012, catches in this area constituted approximately half of the total reported landings. Catches from Greenland were reported for the first time in 2011, and have increased in 2012. In the Icelandic and Faroese fisheries, in the north-western part of the distribution area, mackerel are caught together with herring. In the southern part of the distribution area, Atlantic mackerel (Scomber scombrus) can be caught together with Spanish mackerel (Scomber colias). Catches of both species are reported separately. Catch distribution
Total catch (2012) = 893 kt, where ~98.3% are landings (pelagic trawls, purse-seine nets, and handlines) and 1.7% discards (the latter is only available from a limited number of fleets and considered to be an underestimate).
Effects of the fisheries on the ecosystem There is relatively little bycatch of non-target species in the mackerel fishery, which tends to operate with pelagic trawl gear, purse-seine nets, and handlines. Quality considerations This year ICES was requested to examine the effect of uncertainty in the catch. No specific guidance on the levels of uncertainty were given by the client, however a published study (Simmonds, 2010) had indicated that there was unaccounted mortality which could be explained by errors in reporting historical catches between factors of 1.6 and 3.6 times the reported catches. This range of uncertainty was chosen as the basis for a sensitivity analysis for unaccounted catches prior to 2005. This analysis showed that the assessment model used until 2012 would underestimate stock size if catches have been correctly reported since 2005. Overall the consideration of catch uncertainty was based both on this published evidence of unaccounted mortality and also on anecdotal evidence of the accuracy of the catch information from the fishing industry. This uncertainty was restricted to the period before 2005. After this date more effective catch reporting was instituted. Based on this sensitivity analysis and the perception of uncertainty in historical catches ICES concluded that potential catch for this stock had been underestimated in the recent past and that the previous stock assessment method was no longer an appropriate basis for providing catch advice for this stock. Continued use of this modelling approach would have given landings of approximately 790 000 t. ICES also has available a triennial egg survey, which might be used as a relative index of spawning stock size, and combined with recent average landings to give advice under the ICES approach to data-limited stocks, DLS category 3.2. The 2013 surveys have only just been completed and only a preliminary point estimate of egg production and biomass is available. A final value for the 2013 survey and estimates of precision will be available in 2014. Until the necessary analyses are finalized it is not possible to use the survey in this DLS method because without information on precision it is not possible to determine whether the precautionary buffer should be applied or not. This index is unaffected by the uncertainty in the catch and has been used in the past as an index of SSB within the assessment model. The survey results, taken together with estimates of mortality based on catch, give strong indications that there has been an increase in stock size and that current levels of catch and landings do not pose a threat to the stock. Advice is based on landings from the three most recent years, but this advice is seen as an interim measure. ICES will attempt to incorporate more stock size information in an appropriate assessment model at the benchmark in 2014. Should this approach be unsuccessful a DLS approach will be developed based specifically on the triennial regime of survey data. Scientific basis Assessment No analytic assessment is available. Discards Discards have been included in the assessment since 1978, from Germany, Ireland, the
Netherlands, Spain, and the UK. Discards cannot be quantified accurately and are regarded to be underestimated.
Indicators None. Other information A benchmark is scheduled for 2014. Working group report WGWIDE (ICES, 2013a).
9.4.17 Supporting information October 2013 ECOREGION Widely distributed and migratory stocks STOCK Mackerel in the Northeast Atlantic (combined Southern, Western, and
North Sea spawning components) Reference points Previous reference points are not cited here because the model basis for the assessment has been rejected. Outlook for 2014 No analytical assessment can be presented. The main cause is a change in the perception of the accuracy of the catch data prior to 2005. Sensitivity runs with alternative catch series demonstrated that the assessment model configuration was dependent on the accuracy of the historical catch data series. A benchmark assessment is scheduled for February 2014 which will consider alternative models as well as a suite of possible survey indices not currently used in the assessment. In the interim, considering that recent landings have been stable and that the stock appears to have increased, ICES considers that the current exploitation is appropriate in the short term. Therefore, ICES advises that catches should not increase in relation to the last three years’ average. This corresponds to landings of no more than 889 886 t in 2014. Discards are known to take place, but cannot be quantified accurately; therefore total catches cannot be calculated. ICES approach to data-limited stocks For data-limited stocks for which a biomass index is available, ICES would normally use status quo landings adjusted by the survey index as a harvest control rule. This approach has not been used as the basis for the advice here because the survey is only conducted every third year and results from the most recent year (2013) are preliminary. Given that the survey results are preliminary and that mortality signals are equivocal, ICES is unable to determine if a precautionary buffer according to the data-limited approach should be applied (giving landings = 854 291 t); however, ICES notes that advising an even larger increase in catch, as would be the case otherwise (giving landings = 1 067 863 t), would not be precautionary. ICES is therefore unable to give advice based on the DLS approach and as an interim measure advises not to increase recent landings compared to the last three years (see above). Additional considerations Ecosystem considerations The changes in mackerel distribution and migration have been investigated in an Ad hoc Group on the Distribution and Migration of Northeast Atlantic Mackerel (AGDMM; ICES, 2013b). The accepted consensus of the AGDMM was that there has been an expansion of the distribution of spawning over time in the western component. This expansion has been geographically large, but is thought to contain a marginal proportion of total spawning. There has also been an expansion in the temporal distribution of spawning in the western and southern components to earlier in the year. The distribution of juvenile mackerel is very patchy, and abundance is highly variable between years. A northern expansion of the western component is indicated by the recent summer surveys in the Nordic Seas (IESSNS). Likewise a westward expansion in the summer distribution of adult mackerel has been observed in the Nordic Seas since 2007, as far west as southeast Greenlandic waters. The distribution of fish tends to be less patchy and more spread out during the summer feeding phase. There have also been physical changes in the environment with record high sea temperatures in recent years facilitating a large potential habitat for mackerel. Furthermore, the expansion could in part be due to a reduction in available food, requiring fish to spread out further to find adequate resources. Overwintering in Icelandic waters, never previously observed, occurred in 2010 and 2011 but not 2012, and in recent years (winter 2006/2007 and since 2009) the Faroe Plateau has been used as a nursery area for 0- and 1-group mackerel. The question remains as to whether or not this expansion in distribution of mackerel is permanent or cyclical. Whatever the driving forces behind this are, it is likely to be a dynamic process, including interactions between several factors (stock size, temperature, zooplankton, oceanographic conditions, etc.). While the marginal distribution has changed notably, the spawning area has remained remarkably inert at its core. If oceanographic drivers are influential, then changes are likely to occur on the decadal scale, though the impact of climate change on these processes requires much further research. Likewise, if stock (size and structure) and prey (zooplankton) dynamics are important, then changes are unlikely to be permanent.
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Management considerations
The advice for 2014 results in advised landings of no more than 889 886 tonnes; this is considerably higher than the TACs advised in recent years. The age-based assessment was rejected; therefore, the basis for advice is the average of the most recent three years’ landings. A discussion of the basis for the advice is given in Quality considerations.
The fishery Mackerel is mainly exploited in a directed fishery for human consumption. This fishery tends to target bigger fish and there is evidence of discarding of smaller, less marketable fish. Regulations and their effects Prior to the late 1960s, spawning biomass of North Sea mackerel was estimated to be above 3 million tonnes. Subsequently, overexploitation occurred and recruitment has failed since 1969, leading to a marked decline in the size of the North Sea component. The measures advised by ICES have been aimed at protecting the North Sea spawning component and promoting stock recovery. Despite a small increase in the North Sea spawning up to 1999, the SSB has most recently declined again from 2005 to 2011. The closure of the mackerel fishery in Divisions IVb,c and IIIa throughout the whole year is designed to protect the North Sea component in this area, and also to protect juvenile Western mackerel which are numerous, particularly in Divisions IVb,c during the second half of the year. Unfortunately, the closure has resulted in increased discards of mackerel in the non-directed fisheries (especially horse mackerel fisheries) in these areas as vessels are currently permitted to take only 10% of their catch as mackerel bycatch. As estimates of mackerel bycatch are not available, the reported landings of mackerel in Divisions IIIa and IVb,c from 1997 and onwards underestimate catches because they do not include discarded bycatch. The advised fishery closure of Division IVa during the first half of the year is based on the perception that the Western mackerel enter the North Sea in July/August, and stay there until December before migrating back to their spawning areas. Observations in the late 1990s suggested that this return migration started in mid- to late February. Since 2009, the return migration seems to occur earlier again. According to the EU TAC regulation some smaller quotas are assigned to Divisions IIIa and IVb,c. In the same regulation it is also stated that within the limits of the quota for the western component (Subareas and Divisions VI, VII, VIIIa,b,d,e, Vb (EU), IIa (non-EU), XII, and XIV), a certain quantity of this stock may be caught in Division IVa, but only during the periods 1 January to 15 February and 1 September to 31 December. Existing measures to protect the North Sea spawning component are:
• There should be no fishing for mackerel in Divisions IIIa and IVb,c at any time of the year; • There should be no fishing for mackerel in Division IVa during the period 15 February–31 July; • The 30 cm minimum landing size at present in force in Subarea IV should be maintained.
In the southern area a new Spanish national regulation affecting mackerel catches of Spanish fisheries has been implemented in 2010, distributing the Spanish catch quota by gear (30.5% quota for trawlers, 27.7% for purse-seiners, and 34.6% for artisanal fisheries), half-year, and area. Additionally, a stricter control on mackerel landings was enforced by the Spanish fishery administration. In 2011 the EU introduced a new regulation scheduling payback until 2015 due to overfishing of the mackerel quota allocated to Spain in 2010 (Commission Regulation (EU) No. 165/2011). A similar regulation applied to Scottish and Irish vessels expires in 2012. Other factors Stock components: ICES currently uses the term “Mackerel in the Northeast Atlantic” to define the mackerel present in the area extending from ICES Division IXa in the south to Division IIa in the north, including mackerel in the North Sea and Division IIIa. Catches cannot be allocated specifically to spawning area components on biological grounds, but by convention; catches from the Southern and Western components are separated according to the areas in which these are taken. To keep track of the development of spawning biomass in the different spawning areas, mackerel in the Northeast Atlantic stock are divided into three area components: the Western Spawning Component, the North Sea Spawning Component, and the Southern Spawning Component.
ICES Advice 2013, Book 9 5
Mackerel in the Northeast Atlantic Mainly distributed and fished in ICES Subareas and Divisions IIa, IIIa, IV, V, VI, VII, VIII, and IXa Spawning component Western Southern North Sea Main spawning areas VI, VII, VIIIa,b,d,e, VIIIc, IXa IV, IIIa
The Western component is defined as mackerel spawning in the western area (ICES Divisions and Subareas VI, VII, and VIII a,b,d,e). This component currently accounts for ~75% of the entire Northeast Atlantic stock. Similarly, the Southern component (~22%) is defined as mackerel spawning in the southern area (ICES Divisions VIIIc and IXa). Although the North Sea component has been at an extremely low level since the early 1970s, ICES considers that the North Sea component still exists as a discrete unit (~3%). This component spawns in the North Sea and Skagerrak (ICES Subarea IV and Division IIIaN). Current knowledge of the state of the spawning components is summarized below. Western component: The catches of this component were low in the 1960s, but have increased since. The main catches are taken in directed fisheries by mid-water trawlers and purse-seiners. Large catches of the western component are taken in the northern North Sea, west of Scotland, and in the Nordic seas. A separate assessment for this stock component has not been conducted in recent years, as an extension of the time-series of mackerel in the Northeast Atlantic data allows the estimation of the mean recruitment from 1972 onwards. Preliminary estimates of the SSB of the Western component derived from egg surveys indicate an increase from 3.43 million t in 2010 to 4.30 million t in 2013. North Sea component: Very large catches were taken in the late 1960s in the purse-seine fishery, reaching a maximum of about 1 million tonnes in 1967. The component subsequently collapsed and catches declined to less than 100 000 tonnes in the late 1970s. Annual catches in the last ten years are assumed to be about 10 000 tonnes. Estimates of the SSB of the North Sea component derived from the North Sea egg survey indicate a decrease from 0.22 million t in 2005 to 0.17 million t in 2011. Southern component: Mackerel in this component are taken in a mixture of purse-seine, demersal trawl, line, and gillnet fisheries. The highest catches (87%) from the Southern component are taken in the first half of the year, mainly from Division VIIIc, and consist of adult fish. In the second half of the year, the catches are mainly taken in Division IXa and contain a high proportion of juveniles. Catches from the Southern component increased from about 20 000 t in the early 1990s to about 40 000 tonnes in the early 2000s, reaching a peak at 108 000 tonnes in 2009 and decreasing to 19 000 tonnes in 2011. The 2011 decline was due to pay-back of 18 000 tonnes and tighter regulations. Preliminary estimates of the SSB of the Southern component derived from egg surveys indicate an increase from 0.85 million tonnes in 2010 to 1.27 million tonnes in 2013. Data and methods The advice is partly based on the trend in SSB as reflected by the triennial mackerel egg survey estimates of SSB from 2007 to 2013. The SSB is estimated using the annual egg production method. The survey samples the density of mackerel eggs during six periods from January to July and is designed to cover the spawning distribution during each period. Samples of adult fish are also taken to estimate the fecundity of females. Additional information on data available is described in ICES (2013c). Information from the fishing industry Over the last five years the pelagic industry has encountered large shoals of mackerel over the entire distribution area which has expanded both south and north. This is not confined to one area or one fleet. Based on its qualitative information from the fishing grounds the industry is of the firm view that the abundance of mackerel has increased over the last number of years. The industry is also seeing signs of very good recruitment (above average) over the last number of years, particularly in 2009, 2010 and 2011. The industry believes that the ICES advice for 2014 is too conservative. The widespread distribution over the entire area creates problems with unwanted bycatches for some fleets targeting species other than mackerel. Stakeholders are actively seeking mechanisms that would allow inclusion of fishing industry information into the assessment process, and are involved in a number of pilot projects in this regard. Industry has scaled up its participation in the mackerel RFID tagging project; processing plants in Denmark, Iceland, Ireland and Scotland are now equipped to read mackerel tags, in addition to the existing tag reading facilities in Norway.
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Comparison with previous assessment and advice ICES normally provides advice on mackerel in relation to the management plan. This year, however, ICES was unable to give advice in relation to the management plan as there was no accepted analytical assessment for mackerel in 2013. The assessment was not accepted because the perception it gave of the recent trends in biomass and development of fishing mortality were considered unreliable: the catch data prior to 2005 have been considered by ICES to be unreliable, but analyses carried out this year indicate that the effect of the unreliable historical catch is leading to increasing errors in the perception of the stock, more than had previously been perceived. The problems with the assessment could be addressed using an adapted or different assessment model and ICES has scheduled to undertake this work in 2014. In the absence of an analytical assessment and following the ICES protocol for giving advice, ICES provides an interim advice for 2014, based on average landings. In 2012 the advice was based on the management plan. Sources Burns, F., van Damme, C., Ulleweit, J., Fonn, M., Thorsen, A., and Franco, C. 2013. 2013 Mackerel and Horse
Mackerel Egg Survey. Preliminary Results. WD presented to WGWIDE, 2013. ICES. 2008. EC request on evaluation of long-term management of the NEA mackerel stock and fishery. In Report of
the ICES Advisory Committee, 2008. ICES Advice 2008. Book 9. Section 9.3.2.1. ICES. 2010. Report of the Working Group on Widely Distributed Stocks (WGWIDE), 28 August–3 September 2010,
Vigo, Spain. ICES CM 2010/ACOM:12. ICES. 2011a. Report of the Working Group on Widely Distributed Stocks (WGWIDE), 23–29 August 2011, ICES
Headquarters, Copenhagen, Denmark. ICES CM 2011/ACOM:15. ICES. 2011b. Report of the Working Group on Mackerel and Horse Mackerel Egg Surveys (WGMEGS), 11–15 April
2011, San Sebastian, Spain. ICES CM 2011/SSGESST:07. 109 pp. ICES. 2012. Report of the Working Group on Widely Distributed Stocks (WGWIDE), 21–27 August 2012, Lowestoft,
UK. ICES CM 2012/ACOM:16. ICES. 2013a. Report of the Working Group on Widely Distributed Stocks (WGWIDE), 27 August–02 September 2013,
ICES Headquarters, Copenhagen, Denmark. ICES CM 2013/ACOM:15. ICES. 2013b. Report of the Ad hoc Group on the Distribution and Migration of Northeast Atlantic Mackerel
(AGDMM). ICES CM 2013/ACOM:58. 215 pp.
ICES Advice 2013, Book 9 7
Table 9.4.17.1 Mackerel in the Northeast Atlantic. Advice, management, and catch data for the combined area. Year ICES
Advice Predicted catch corresp. to advice
Total agreed TAC3
Official
landings5 Disc.1
slip ICES catch2,4
1987 Given by stock component 442 616 11 655 1988 Given by stock component 610 622 36 680 1989 Given by stock component 532 576 7 590 1990 Given by stock component 562 580 16 628 1991 Given by stock component 612 609 31 668 1992 Given by stock component 707 729 25 760 1993 Given by stock component 767 784 18 825 1994 Given by stock component 837 794 5 821 1995 Given by stock component 645 729 8 756 1996 Significant reduction in F - 452 509 11 564 1997 Significant reduction in F - 470 517 19 570 1998 F between 0.15 and 0.2 498 549 627 8 667 1999 F of 0.15 consistent with PA 437 562 585 n/a 640 2000 F=0.17: Fpa 642 612 655 2 738 2001 F=0.17: Fpa 665 670 660 1 737 2002 F=0.17: Fpa 694 683 685 24 773 2003 F=0.17: Fpa 542 583 600 9 670 2004 F=0.17: Fpa 545 532 587 11 650 2005 F=0.15 to 0.20 [320–420] 422 447 20 543 2006 F=0.15 to 0.20 [373–487] 444 3186 18 473 2007 F=0.15 to 0.20 [390–509] 502 558 8 579 2008 F=0.15 to 0.20 [349–456] 458 420 27 611 2009 F=0.15 to 0.20 [443–578] 6057 442 13 735 2010 harvest control rule [527–572] 8858 862 7 869 2011 See scenarios 529–672 9598 930 9 939
2012 Follow the management plan [586–639] 9278 877 15 893
2013 Follow the management plan [497–542] 9068
2014 Recent landings (3years) < 889.886
Weights in thousand tonnes. 1Data on discards and slipping from only two fleets. 2Landings and discards from Divisions and Subareas IIa, IIIa, IV, V, VI, VII, VIII, and IXa. 3For all areas, except some catches in international waters in Subarea II. 4Catches updated in 2003 with revisions from SGDRAMA in 2002. 5 Updated with ICES FishStats data. 6 Incomplete. 7 Does not include the unilateral Norway/Faroe Islands TAC first declared in 2009, nor the Icelandic TAC. 8 No internationally agreed TAC for 2010, 2011, and 2012. Values presented are the sum of unilateral TACs.
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Table 9.4.17.2 Mackerel in the Northeast Atlantic. Advice, management, and catch data for the Western component. Year ICES
Advice Predicted catch corresp. to advice
Agreed TAC1
Disc. slip
ICES catch2,4
1987 SSB = 1.5 mill. t; TAC 380 405 11 633 1988 F = F0.1; TAC; closed area; landing size 430 573 36 656 1989 Halt SSB decline; TAC 355 495 7 571 1990 TAC; F = F0.1 480 525 16 606 1991 TAC; F = F0.1 500 575 31 647 1992 TAC for both 1992 and 1993 670 670 25 742 1993 TAC for both 1992 and 1993 670 730 18 805 1994 No long-term gains in increased F 8313 800 5 796 1995 20% reduction in F 530 608 8 728 1996 No separate advice - 422 11 529 1997 No separate advice - 416 19 529 1998 No separate advice - 514 8 623 1999 No separate advice - 520 0 597 2000 No separate advice - 573 2 703 2001 No separate advice - 630 1 694 2002 No separate advice - 642 24 723 2003 No separate advice - 548 9 644 2004 No separate advice - 500 11 615 2005 No separate advice - 397 20 494 2006 No separate advice - 4185 17 420 2007 No separate advice - 472 8 519 2008 No separate advice - 431 27 552 2009 No separate advice - 569 13 627 2010 No separate advice - ---6 4 817 2011 No separate advice - ---6 8 920 2012 No separate advice - ---6 11 864 2013 No separate advice - ---6 2014 No separate advice -
Weights in thousand tonnes. 1TAC for mackerel taken in all Divisions and Subareas VI, VII, VIIIa,b,d, Vb, IIa, IIIa, and IVa. 2Landings and discards of the Western component; includes some catches from the North Sea component. 3Catch at status quo F. 4Catches updated in 2003 with revisions from SGDRAMA in 2002. 5Revised from previous year (was 392). 6 No internationally agreed TAC.
ICES Advice 2013, Book 9 9
Table 9.4.17.3 Mackerel in the Northeast Atlantic. Advice, management, and catch data for the North Sea component. Year ICES
Advice Predicted catch corresp. to advice1
Agreed TAC2
ICES catch3
1987 Lowest practical level LPL 55 3 1988 Closed areas and seasons; min. landing size; bycatch regulations LPL 55 6 1989 Closed areas and seasons; min. landing size; bycatch regulations LPL 49.2 7 1990 Closed areas and seasons; min. landing size; bycatch regulations LPL 45.2 10 1991 Closed areas and seasons; min. landing size; bycatch regulations LPL 65.5 -4 1992 Closed areas and seasons; min. landing size; bycatch regulations LPL 76.3 -4 1993 Maximum protection; closed areas and seasons; min landing size LPL 83.1 -4 1994 Maximum protection; closed areas and seasons; min landing size LPL 95.7 -4 1995 Maximum protection; closed areas and seasons; min landing size LPL 76.3 -4 1996 Maximum protection; closed areas and seasons; min landing size LPL 52.8 -4 1997 Maximum protection; closed areas and seasons; min landing size LPL 52.8 -4 1998 Maximum protection; closed areas and seasons; min landing size LPL 62.5 -4 1999 Maximum protection; closed areas and seasons; min landing size LPL 62.5 -4 2000 Maximum protection; closed areas and seasons; min landing size LPL 69.7 -4 2001 Maximum protection; closed areas and seasons; min landing size LPL 71.4 -4 2002 Maximum protection; closed areas and seasons; min landing size LPL 72.9 -4 2003 Maximum protection; closed areas and seasons; min landing size LPL 62.5 -4 2004 Maximum protection; closed areas and seasons; min landing size LPL 57.7 -4 2005 Maximum protection; closed areas and seasons; min landing size LPL 44.9 -4 2006 Maximum protection; closed areas and seasons; min landing size LPL 47.1 -4 2007 Maximum protection; closed areas and seasons; min landing size LPL 53.1 -4 2008 Maximum protection; closed areas and seasons; min landing size LPL 48.6 -4 2009 Maximum protection; closed areas and seasons; min landing size LPL 63.8 -4 2010 Maximum protection; closed areas and seasons; min landing size LPL - -4 2011 Maximum protection; closed areas and seasons; min landing size LPL - -4 2012 Maximum protection; closed areas and seasons; min landing size LPL - -4 2013 Maximum protection; closed areas and seasons; min landing size LPL - -4 2014 Maximum protection; closed areas and seasons; min landing size LPL -
Weights in thousand tonnes. 1Subarea IV and Division IIIa. 2TAC for Subarea IV, Divisions IIIa, IIIb,c,d (EU zone), and Division IIa (EU zone). 3Estimated landings of the North Sea component. 4No information. LPL = Lowest Practical Level.
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Table 9.4.17.4 Mackerel in the Northeast Atlantic. Advice, management, and catch data for the Southern component.
Year ICES Advice
Predicted catch corresp. to advice
Agreed TAC1
ICES Catch2
1987 Reduce juvenile exploitation - 36.57 22 1988 Reduce juvenile exploitation - 36.57 25 1989 No advice - 36.57 18 1990 Reduce juvenile exploitation - 36.57 21 1991 Reduce juvenile exploitation - 36.57 21 1992 No advice - 36.57 18 1993 No advice - 36.57 20 1994 No advice - 36.57 25 1995 No advice - 36.57 28 1996 No separate advice - 30.00 34 1997 No separate advice - 30.00 41 1998 No separate advice - 35.00 44 1999 No separate advice - 35.00 44 2000 No separate advice - 39.20 36 2001 No separate advice - 40.18 43 2002 No separate advice - 41.10 50 2003 No separate advice - 35.00 26 2004 No separate advice - 32.31 35 2005 No separate advice - 24.87 50 2006 No separate advice - 26.18 53 2007 No separate advice - 29.61 63 2008 No separate advice - 27.01 60 2009 No separate advice - 35.83 108 2010 No separate advice - 33.88 52 2011 No separate advice - 37.14 19 2012 No separate advice - 36.74 29 2013 No separate advice - 31.16 2014 No separate advice -
Weights in thousand tonnes. 1Division VIIIc, Subareas IX and X, and CECAF Division 34.1.1 (EU waters only). 2Catches updated in 2003 with revisions from SGDRAMA in 2002.
ICES Advice 2013, Book 9 11
Table 9.4.17.5a Mackerel in the Northeast Atlantic (combined Southern, Western, and North Sea spawning components). Catches (in tonnes) by country 1988–2012 (data submitted by Working Group members).
Table 9.4.17.5b Mackerel in the Northeast Atlantic (combined Southern, Western, and North Sea spawning components). Catches (in tonnes) by country 1988–2012 (cont.) (data submitted by Working Group members).
Table 9.4.17.6a Mackerel in the Northeast Atlantic (combined Southern, Western, and North Sea spawning components). Catches by area. Discards not estimated prior to 1978 (data submitted by Working Group members).
YEAR SUBAREA VI SUBAREA VII AND DIVISIONS VIIIABDE
Table 9.4.17.6b Mackerel in the Northeast Atlantic (combined Southern, Western, and North Sea spawning components). Catches by area (cont.). Discards not estimated prior to 1978 (data submitted by Working Group members).
YEAR SUBAREA VI SUBAREA VII AND DIVISIONS VIIIABDE
ICES evaluated the following harvest control rule contained in the Norway, Faroe Islands, and EU management plan for mackerel in the Northeast Atlantic, agreed in October 2008:
1. For the purpose of this long-term management plan, “SSB” means the estimate according to ICES of the spawning stock biomass at spawning time in the year in which the TAC applies, taking account of the expected catch.
2. When the SSB is above 2,200,000 tonnes, the TAC shall be fixed according to the expected landings, as advised by ICES, on fishing the stock consistent with a fishing mortality rate in the range of 0.20 to 0.22 for appropriate age groups as defined by ICES.
3. When the SSB is lower than 2,200,000 tonnes, the TAC shall be fixed according to the expected landings as advised by ICES, on fishing the stock at a fishing mortality rate determined by the following:
Fishing mortality F = 0.22* SSB/ 2,200,000
4. Notwithstanding paragraph 2, the TAC shall not be changed by more than 20% from one year to the next, including from 2009 to 2010.
5. In the event that the ICES estimate of SSB is less than 1,670,000 tonnes, the Parties shall decide on a TAC which is less than that arising from the application of paragraphs 2 to 4.
6. The Parties may decide on a TAC that is lower than that determined by paragraphs 2 to 4. 7. The Parties shall, as appropriate, review and revise these management measures and strategies on the basis of